‘The Flash’ Season 3 Finale Promo, Spoilers: Iris Is Alive; Season 4 Synopsis Released
Iris West does not die in "The Flash" Season 3 Finale. That is, according to the synopsis for Season 4, which teased she lives to help Barry fight crime in Central City.
The penultimate episode saw Savitar kill Iris (Candice Patton) despite Barry and the team's attempts to prevent her death. Barry had to relive her death over again although the synopsis for Season 4 hinted that she is still alive when "The Flash" Season 3 Finale opens.
Cosmic Book News shared the synopsis for Season 4, which teased that Iris is still alive in "The Flash" Season 3 Finale. The synopsis recalled how Barry got his speed powers and how he created Flashpoint, which brought the villain Savitar who changed the lives of Caitlin and Wally forever. However, "with the help of his adoptive father, Joe, his lifelong best friend and love interest Iris, and his friends at S.T.A.R. Labs - Cisco, C.S.I Julian and H.R.- Barry continues to protect the people of Central City from the meta-humans that threaten it," read the synopsis.
It is safe to assume that Iris is alive in "The Flash" Season 3 Finale given the synopsis for Season 4. This means that whoever Savitar killed is not Barry's fiancée. Nor is it H.R. Wells, whom fans speculated took Iris' place using the transmogrifier. This device can turn anyone into another person, by altering his or her physical image.
According to Collider, H.R. Wells let Iris live through Season 4 when he switched places with her during that time Savitar was speeding around Barry. He could have asked Wally (who may have regained his health) to put him on Iris' place on the ground. This would explain why Iris is alive in "The Flash" Season 3 Finale and why H.R. was not on the roof with the Speed Force bazooka, as what Cisco initially saw from his vision.
Likewise, leaked set photos and footage from the filming of "The Flash" Season 3 Finale saw Iris is still alive. This means she returns to Season 4. Interestingly, H.R. is also in the video (or it could just be Harrison from Earth 2).